| 1. |
- Del Duca, V., et al.
(författare)
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All-Order Amplitudes at any Multiplicity in the Multi-Regge Limit
- 2020
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 124:16
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Tidskriftsartikel (refereegranskat)abstract
- We propose an all-loop expression for scattering amplitudes in planar N = 4 super Yang-Mills theory in multi-Regge kinematics valid for all multiplicities, all helicity configurations, and arbitrary logarithmic accuracy. Our expression is arrived at from comparing explicit perturbative results with general expectations from the integrable structure of a closely related collinear limit. A crucial ingredient of the analysis is an all-order extension for the central emission vertex that we recently computed at next-to-leading logarithmic accuracy. As an application, we use our all-order formula to prove that all amplitudes in this theory in multi-Regge kinematics are single-valued multiple polylogarithms of uniform transcendental weight.
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| 2. |
- Del Duca, Vittorio, et al.
(författare)
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The gluon Regge trajectory at three loops from planar Yang-Mills theory
- 2022
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Ingår i: Journal of High Energy Physics (JHEP). - : Springer Nature. - 1126-6708 .- 1029-8479. ; :1
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Tidskriftsartikel (refereegranskat)abstract
- We compute the three-loop leading-colour corrections to the Yang-Mills Regge trajectory and gluon impact factor. Conjecturing that, in analogy with N = 4 super Yang-Mills (SYM), in a suitable scheme N-c-subleading terms are absent from the three-loop Regge trajectory, we understand our result as the first computation of the pure gauge, or n(f) = 0, part of the QCD three-loop Regge trajectory. The results are presented both for the bare and renormalised amplitudes and are consistent with predictions from infrared factorisation along with reproducing known results in planar N = 4 SYM through a maximal weight truncation. We also include the dependence on a Regge factorisation scale to facilitate future applications in BFKL theory at next-to-next-to leading logarithmic accuracy.
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| 3. |
- Dorigoni, Daniele, et al.
(författare)
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Modular graph forms from equivariant iterated Eisenstein integrals
- 2022
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Ingår i: Journal of High Energy Physics (JHEP). - : Springer. - 1126-6708 .- 1029-8479. ; :12
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Tidskriftsartikel (refereegranskat)abstract
- The low-energy expansion of closed-string scattering amplitudes at genus one introduces infinite families of non-holomorphic modular forms called modular graph forms. Their differential and number-theoretic properties motivated Brown's alternative construction of non-holomorphic modular forms in the recent mathematics literature from so-called equivariant iterated Eisenstein integrals. In this work, we provide the first validations beyond depth one of Brown's conjecture that equivariant iterated Eisenstein integrals contain modular graph forms. Apart from a variety of examples at depth two and three, we spell out the systematics of the dictionary and make certain elements of Brown's construction fully explicit to all orders.
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| 4. |
- Duhr, Claude, et al.
(författare)
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Full-Color Two-Loop Four-Gluon Amplitude in N=2 Supersymmetric QCD
- 2019
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Ingår i: Physical Review Letters. - : American Physical Society. - 0031-9007 .- 1079-7114. ; 123:24
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Tidskriftsartikel (refereegranskat)abstract
- We present the fully integrated form of the two-loop four-gluon amplitude in N = 2 supersymmetric quantum chromodynamics with gauge group SU(N-c) and with N-f massless supersymmetric quarks (hypermultiplets) in the fundamental representation. Our result maintains full dependence on N-c and N-f, and relies on the existence of a compact integrand representation that exhibits the duality between color and kinematics. Specializing to the N = 2 superconformal theory, where N-f = 2N
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| 5. |
- Duhr, Claude, et al.
(författare)
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The Full-Color Two-Loop Four-Gluon Amplitude in N=2 Super-QCD
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- We present the fully integrated form of the two-loop four-gluon amplitude in N=2 supersymmetric quantum chromodynamics with gauge group SU(Nc) and with Nf massless supersymmetric quarks (hypermultiplets) in the fundamental representation. Our result maintains full dependence on Nc and Nf, and relies on the existence of a compact integrand representation that exhibits the duality between color and kinematics. Specializing to the N=2 superconformal theory, where Nf=2Nc , we obtain remarkably simple amplitudes that have an analytic structure close to that of N=4 super-Yang-Mills theory, except that now certain lower-weight terms appear. We comment on the corresponding results for other gauge groups.
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| 6. |
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| 7. |
- Gerken, Jan, 1991, et al.
(författare)
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Towards closed strings as single-valued open strings at genus one
- 2022
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Ingår i: Journal of Physics A: Mathematical and Theoretical. - : IOP Publishing. - 1751-8121 .- 1751-8113. ; 55:2
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Tidskriftsartikel (refereegranskat)abstract
- We relate the low-energy expansions of world-sheet integrals in genus-one amplitudes of open- and closed-string states. The respective expansion coefficients are elliptic multiple zeta values (eMZVs) in the open-string case and non-holomorphic modular forms dubbed 'modular graph forms (MGFs)' for closed strings. By inspecting the differential equations and degeneration limits of suitable generating series of genus-one integrals, we identify formal substitution rules mapping the eMZVs of open strings to the MGFs of closed strings. Based on the properties of these rules, we refer to them as an elliptic single-valued map which generalizes the genus-zero notion of a single-valued map acting on MZVs seen in tree-level relations between the open and closed string.
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| 8. |
- Kälin, Gregor, et al.
(författare)
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Infrared and transcendental structure of two-loop supersymmetric QCD amplitudes
- 2020
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Ingår i: Journal of High Energy Physics (JHEP). - : SPRINGER. - 1126-6708 .- 1029-8479. ; :1
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Tidskriftsartikel (refereegranskat)abstract
- Using a careful choice of infrared (IR) subtraction scheme, we demonstrate cancellation of all terms with transcendental weights 0, 1, 2 from the finite part of the full-color two-loop four-gluon N = 2 supersymmetric QCD amplitude, with N-f massless supersymmetric quarks. This generalizes the previously observed cancellation of weight-2 terms in the superconformal theory, where N-f = 2N(c) for gauge group SU(N-c). The subtraction scheme follows naturally both from general IR factorization principles and from an integrand-level analysis of divergences in this amplitude. The divergences are written in terms of scalar triangle integrals whose expressions are known to all orders in the dimensional regulator E = (4 - D)/2. We also present integrated expressions for the full-color two-loop four-point amplitudes with both matter and vectors on external legs in which lower-weight terms also cancel using an appropriate IR scheme. This provides us with values for the two-loop cusp, gluonic, and quark anomalous dimensions in N = 2 supersymmetric QCD, which are cross-checked between the three different amplitudes.
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